#include <bits/stdc++.h>
using namespace std;

#define int int64_t
#define endl "\n"

using PII = pair<int, int>;
using TII = tuple<int, int, int>;
template<class T> using V = vector<T>;
using i64 = long long;
using i128 = __int128;
using u64 = unsigned long long;

#define FOR(i, a, b) for (int i = (int)(a); i <= (int)(b); i++)
#define FOR2(i, a, b, c) for (int i = (int)(a); i <= (int)(b); i += c)
#define FORD(i, b, a) for (int i = (int)(a); i >= (int)(b); i--)
#define FORD2(i, b, a, c) for (int i = (int)(a); i >= (int)(b); i -= c)
#define ALL(a) a.begin(), a.end()
#define RALL(a) a.rbegin(), a.rend()
#define lowbit(x) ((x) & (-x))
#define RE return;
#define Yes cout << "Yes" << endl;
#define YES cout << "YES" << endl;
#define No cout << "No" << endl;
#define NO cout << "NO" << endl;
#define pb push_back
#define eb emplace_back
#define fi first
#define se second
#define sz(x) (int)(x).size()

void solve() {
    int n;
    string s;
    cin >> n >> s;
    int top = 0;
    V<int> a;
    int lst = 0;
    a.eb(0);
    FOR(i, 1, n - 1) {
        if (s[i] != s[i - 1]) a.eb(i - lst), lst = i, top++;
    }
    a.eb(n - lst);
    top++;
    int pos = 1;
    FOR(i, 1, top) {
        while (pos <= top && a[pos] == 1) pos++;
        a[pos]--;
        if (pos > top) {
            cout << (i - 1 + (top - i + 2) / 2) << endl;
            RE;
        }
        if (pos <= i) pos = i + 1;
    }
    cout << top << endl;
}

signed main() {
    int Task = 1;

    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cin >> Task;
    while (Task--) {
        solve();
    }

    return 0;
}
